RIP Duck
He had one of the great lines in the first Blues Brothers movie:
"We had a band powerful enough to turn goat piss into gasoline!"
I also recall the video (not sure if it's Monterey pop extended version or more likely the Norwegian TV Stax/Volt revue) that he had this tremendous smile on his face while playing with Booker T & the MGs and the Mar-keys.
Both are highly recommended if you like 60s soul without the Motown teeny bopper fluff.